The present invention No. I relates to a high purity 3-alkoxy-1-propanol, particularly, a high purity 3-methoxy-1-propanol, in which acrolein and an alcohol, particularly, methanol are employed as raw materials, and a method for the preparation thereof.
The present invention No. II relates to a cleaning agent for lithography which is employed for dissolving or removing a resist, etc., and in more detail, a cleaning agent for lithography which can be usefully employed for cleaning a coating apparatus such as an inside of a coater cup, for removing an unnecessary resist in coating the resist or on a base plate after coating, for removing a resist from the base plate after attaining use purpose of the resist, and for cleaning and rinsing the base plate after removing a resist.
The present invention No. III relates to a rinsing liquid for lithography and, in more detail, it relates to a rinsing liquid for lithography which is useful for dissolving or removing cured and uncured unnecessary resist and a reflection protecting-layer from an integrated circuit element, a color filter, a base plate for a liquid crystal display element, etc., or coating apparatus for a resist, etc.
The present invention No. IV relates to a solvent for a resist composition which is employed as an object for irradiating a corpuscular beam such as an ultraviolet ray, a far ultraviolet ray, an X-ray, and an electron beam, etc., and relates to a resist composition characterized by the use thereof and, in more detail, it relates to a solvent which provides resist composition which is excellent in safeness during the use, coatability, residual ratio of a layer during development, uniformity of line width of a pattern after development, and resist adhesion during development, and it relates to a resist composition composed of the solvent and a resist resin.
The present invention No. V relates to a photo-curable resin composition which is preferred as an etching resist or a solder resist which is employed in, particularly, a preparation stage of a printed circuit board.
3-methoxy-1-propanol is also named 1,3-propane diol methylether, and it has an alcoholic hydroxyl group and methyether group. The alcoholic hydroxyl group has esterification reactivity, etherification reactivity, and halogenation reactivity, and it is an important compound as many useful compounds, particularly, raw materials for medicines and agricultural chemicals, and functional solvents.
In the case that a variety of reactions are conducted using 3-methoxy-1-propanol, if alcoholic impurities are contained in 3-methoxy-1-propanol, since a reaction of the alcoholic impurities also proceeds under same reaction conditions as in 3-methoxy-1-propanol, compounds derived from the alcoholic impurities end to be contained in a final product obtained. This causes a serious problem in the case that 3-methoxy-1-propanol is employed as, particularly, a raw materials for medicines and agricultural chemicals, and functional solvents.
As a method for the preparation of 3-methoxy-1-propanol, for example, U.S. Pat. No. 2,495,313 describes a method in which methanol and acrolein are employed as raw materials, and JP-A-08113546 Official Gazette describes a method in which methanol and 3-chloro-1-propanol are employed as raw materials. However, there are not described the amount of the alcoholic impurities contained in 3-methoxy-1-propanol at all.
JP-A-07025821 Official Gazette describes a method for the preparation of 3-methoxy-1-propanol by hydrogenation of a product obtained by allowing to react methanol with acrolein under the presence of a basic catalyst, followed by allowing to react with acetic acid under the presence of an acidic catalyst, and a solvent containing thereof. Further, JP-A-10306050 Official Gazette describes an etheralcohol-based solvent containing 3-methoxy-1-propanol, however, there is only obtained a product having purity of 98.4% or so, a kind and amount of the impurities are not described in all the prior arts and, the prior arts are not aware a problem by the impurities.
In the preparation of an integrated circuit element, a color filter, a liquid crystal display element, and a printed circuit board, etc., fine processing is demanded and, in order to satisfy the demand, there has been conventionally employed a lithography technology using a resist.
As a conventionally well known or publicly-known resist, there have been employed a screen ink, dry-film resist, electrodeposition resist, and liquid resist, etc., and, of those, there has been recently attention to the liquid photoresist. The liquid photoresist includes a positive type one and a negative type one.
In the liquid photoresist compared to the dry-film resist, since the thickness of resist coating layer can be thinned as well as in the electrodeposition resist, identical or more excellent dissolution can be expected as in the electrodeposition resist in formability of a micro-pattern. Further, a bath control is not required as in the electrodeposition resist, and since it can become more decreased in price from a viewpoint of plant investment than in the electrodeposition resist, it is hopeful as a preparation method of a micro-pattern.
As solvents to be employed for the resist composition, a variety of solvents have been conventionally known, and an appropriate solvent is selectively employed in consideration of solubility to a resist, coatability, sensitivity, developability, and properties of a pattern formed. On the other hand, independently upon a performance such as resist-forming properties, many solvents usually include a problem in view of safeness to human bodies. It is actual circumstances that the safeness to human bodies, particularly, recently becomes attached importance, and solvents are selected also in consideration of the safeness to human bodies. For example, although ethylene glycol monoethylether acetate has been known as a solvent which is excellent in the properties such as solubility, coatability, resist forming ability, it has not become quite employed as a solvent for resist after indication of a problem of the safeness to human bodies, and there has become mainly employed propylene glycol monoethylether acetate, etc., instead of that as a solvent having safeness (for example, JP-B-91001659, JP-B-92056973, and JP-B-92049938 Official Gazettes). Further, as solvents having safeness, ethyl lactate and methyl-n-amylketone, etc. are known other than propylene glycol monomethylether acetate. However, the solvents which are regarded as a solvent having high safeness compared to ethylene glycol monoethylether acetate include a problem that there are not sufficient properties such as a resist-forming ability and solubility to resist materials. For example, in the case of propylene glycol monomethylether acetate, there have been problems of the ratio of remaining solvents in a coating layer after coating a resist onto a base plate, uniformity of line width, and a fall of adhesion of a resist layer during development. This is caused by that although propylene glycol monomethylether acetate itself is a solvent having quick evaporation rate, in the case that it is employed as a solvent for a resist composition, evaporation proceeds at a coating surface alone and a so-called ultra-thin layer is formed at the surface, whereby, it becomes difficult for the solvent remained in an inside of coating surface to evaporate.
Still further, it is known that propylene glycol monomethylether acetate is poorer in solubility to a resin and an initiator compared to ethylene glycol monoethylether acetate.
Also, JP-A-06324483 and JP-A-06324499 Official Gazettes disclose a technology for improving solubility to a resin and an initiator, etc. using a xcex2-type propylene glycol monoalkylether acetate (that is, 1-alkoxy-2-propanol acetate). However, the propylene glycol-based solvents are still insufficient in view of solubility to a resin and an initiator because of the presence of substituted groups at 1,2-position. For that reason, there has been desired a solvent in which safeness is high, which is excellent in solubility to a resin and an initiator, and in which performances such as resist formability are improved.
And also, in the case that a large amount of impurities are contained in solvents, there is a problem that it is difficult to obtain a resist layer having a stable quality because of different evaporation rate of the solvents.
In the preparation of an integrated circuit element, etc. using a lithography technology, the above-described resist composition is coated by a publicly-known method on a base plate such as a silicone base plate and glass base plate. After having been coated, solvents are removed by baking to prepare a resist layer and, a reflection protecting-layer is optionally formed on the resist layer, followed by exposing to a various radiation rays such as an ultraviolet ray, a far ultraviolet ray, an electron beam, and an X-ray, by optionally baking, and by developing to form a resist pattern.
After that, optionally, a baking is further conducted, followed by conducting an etching treatment, etc. of the base plate and by usually removing the resist.
Coating of the above-described resist composition is conducted by various publicly-known methods such as a spin-coating, roll-coating, reverse roll-coating, casting coating, doctor-coating, and dip-coating methods. For example, in the preparation of an integrated circuit element, the spin-coating method is mainly employed as a coating method for a resist. In the spin-coating method, a resist solution is dropped on a base plate and, the resist solution dropped is cast toward a periphery of the base plate by rotation of the base plate and, an excessive resist solution is shakenly removed from the periphery of the base plate to form a resist layer having a desired thickness.
The excessive resist solution is partially remained in a coater-cup, and it is solidified by evaporation of solvents with a lapse of time. Solidified substance becomes fine powder, and it is scattered and adheres to the resist base plate, resulting in that it causes a defect on a resist pattern. In order to prevent a phenomenon, the coater-cup must be cleaned every treatments of several or several tens base plates.
Further, in the case that a resist layer having a desired thickness is formed on a base plate by the spin-coating method, there is a drawback that the resist solution is partially turned in a back surface of the base plate, or the resist solution is remained in a larger thickness than in other portion at periphery of the base plate, so-called beads are formed. For that reason, it is required that an unnecessary resist or the beads are removed from the circumference of side surface or back surface in the base plate.
Still further, even in the case of the coating methods other than the spin-coating method, a resist occasionally adheres at an unnecessary portion as well as in the spin-coating method. Also, a resist is usually removed after conducting a treatment of a base plate by etching, and the resist is removed by dissolving using organic solvents even in a removal step. After that, the base plate in which the resist is removed is usually washed by pure water, etc. in order to prepare a surface of the base plate not stained by removing micro particles remained at surface, and it moves to a next step. Herein, in the case that a solvent for removing a resist is a water-insoluble organic solvent or an amine-based organic solvent, there is often arranged a step for rinsing by a clean water-soluble solvent without washing by the pure water immediately after a removing step. The reason is as follows. In the case that the water-insoluble organic solvent is employed as a removing solution, it is conducted in order to prevent that a resist dissolving in the solvent adheres again on the base plate, or, in the case that the amine-based organic solvent is employed as a removing solution in order to replace the water-insoluble organic solvent existing on the surface of the base plate with the water-soluble organic solvent and to smooth replacement with pure water, it is conducted in order to avoid a corrosion of a metallic base plate showing an alkaline property by remaining of the solvents in water.
And also, it is also required that a coating apparatus is cleaned in order to reuse the coating apparatus for a next preparation or in order to use as a coating apparatus for a different kind of materials after the completion of coating and, in the case of an integrated circuit element having a reflection protecting-layer between a base plate and a resist layer, the reflection protecting-layer is optionally removed by a solvent after forming a resist pattern.
As described hereinabove, solvents for cleaning or rinsing are employed for removing the resist or the reflection protecting-layer, for preventing peeling and formation of beads and, for cleaning or rinsing a coating apparatus in the lithography technology, and there have been known (the previously-described JP-A-92049938 Official Gazette, etc.) a variety of solvents composed of conventional organic solvents alone. And, it is actual circumstances that there is demanded an excellent solubility to a reflection protecting-layer or a resist and an excellent removing property in such the solvents.
Besides, an aqueous solution becomes recently often employed in the case of preparation of a reflection protecting-layer. And, for the reflection protecting-layer formed from an aqueous solution, there has been also desired a supply of a rinsing liquid which has a preferred rinsing effect such as a shortened dissolving time and, further, which also satisfies safeness to a fire and in handling.
In JP-A-05188598, JP-A-06069190, and JP-A-06148896 Official Gazettes, there is proposed a reflection protecting-layer formed from an aqueous solution. However, it has been difficult to simultaneously satisfy the demand by conventional rinsing liquids.
As described hereinabove, something of conventional solvents for resist do not show a sufficient dissolving ability to resist, and those take a long time or a large amount for sufficiently cleaning and rinsing, and something of conventional solvents have a very high toxicity, as a result, there are not solvents which simultaneously satisfy an excellent dissolving ability and safeness to human body, etc., and there have been desired the solvents which simultaneously satisfy an excellent dissolving ability and safeness to human body.
The fact is the same even in the case of the preparation of a color filter and a liquid crystal display element in addition to the preparation of an integrated circuit element.
Purpose of the present invention No. I is to provide a 3-alkoxy-1-propanol having the content of alcoholic impurities of not more than 0.3%, particularly, a high purity 3-methoxy-1-propanol, and a method for the preparation thereof.
Purpose of the present invention No. II is to provide a cleaning agent for lithography which does not have the above-described drawbacks, that is, which can be usefully employed for cleaning a coating apparatus such as an inside of a coater-cup, for removing an unnecessary resist on a base plate during or after coating a resist, for removing a resist from a base plate after having attained the purpose of the resist, and for cleaning the base plate after having removed the resist, and which also has a high dissolving ability capable of quickly cleaning in a short cleaning time of period by a small use amount, and high safeness to human body.
Purpose of the present invention No. III is to provide a rinsing liquid which does not have the above-described drawbacks, that is, which is employed for rinsing a resist formed from an organic solvent solution and a reflection protecting-layer formed from an organic solvent solution or an aqueous solution, and which has a dissolving ability and a removing ability to the resist and a reflection protecting-layer, and in which danger of fire is improved, and which is easy in handling based on Fire Defence Law in Japan, etc.
Purpose of the present inventions No. IV and V is to solve the problems in the above-described prior arts, and to provide a liquid resist composition in which a dissolving ability is improved in the preparation of the resist composition and stability is jumpingly elevated and, an amount of a residual solvent in a resist layer is decreased in the preparation of the resist layer, and there are improved properties such as the ratio of remaining solvents, uniformity of line width, and adhesion, etc. of a resist layer during development, and in which a homogeneity and delicateness are improved, and provides a solvent to be employed for the composition.
The present inventors, as a result of an intensive investigation, have found out that the above-described problems can be solved by the following matters, and the present invention has been completed.
In the present invention No. I, it was found out that a 3-alkoxy-1-propanol having the content of alcoholic impurities of not more than 0.3% by weight, particularly, 3-methoxy-1-propanol can be obtained through a step in which a 3-alkoxy-1-propanal is produced by allowing to react acrolein with an alcohol such as methanol using acrolein having the content of propionaldehyde of not more than 1% by weight as a raw material, a step in which the 3-alkoxy-1-propanal is hydrogenated to produce a 3-alkoxy-1-propanol in a state of residual aldehyde concentration of not more than 0.5% by weight in a crude liquid of a hydrogenation reaction, and an evaporation step of the 3-alkoxy-1-propanol, and the present invention No. I has been completed.
In the present invention No. II, there is employed a solvent (a) composed of a 1,3-propanediol alkylether, 1,3-propanediol alkylether acetate, or a mixture thereof as a cleaning agent, and the present invention No. II has been completed.
In the present invention No. III, it was found out that a dissolving ability or removing ability to a resist or a reflection protecting-layer is elevated by employing a mixture of the solvent (a) with water as a cleaning agent compared to a case composed of a water-soluble organic solvent alone, and a flash point of a mixed solvent is elevated by containing water, and danger such as fire is also reduced, that is, there is also improved safeness in handling based on Fire Defence Law, and the present invention No. III has been completed.
The present invention No. IV can be attained by employing the solvent (a) as a solvent for a resist resin, etc.
The present invention No. V can be attained by employing a resin composition composed of the solvent (a) and a specified modified copolymer as a resist composition.
The present invention 1 provides a high purity 3-alkoxy-1-propanol having the content of alcoholic impurities of not more than 0.3% by weight.
The present invention 2 provides a high purity 3-alkoxy-1-propanol as described in the present invention 1, in which the 3-alkoxy-1-propanol is 3-methoxy-1-propanol.
The present invention 3 provides a high purity 3-alkoxy-1-propanol as described in the present invention 2, in which the alcoholic impurities are 2-methyl-1-pentanol and/or methanol.
The present invention 4 provides a method for the preparation of a high purity 3-alkoxy-1-propanol characterized in that a 3-alkoxy-1-propanal is produced by allowing to react acrolein with a linear or branched alcohol having a carbon number of 1-4 using acrolein having the content of propionaldehyde of not more than 1% by weight as a raw material, a 3-alkoxy-1-propanol is produced by a hydrogenation reaction of a reaction mass using hydrogen under the presence of a catalyst, followed by recovering through a distillation the 3-alkoxy-1-propanol having the content of alcoholic impurities of not more than 0.3% by weight from a crude solution in the hydrogenation reaction.
The present invention 5 provides a method for the preparation of a high purity 3-alkoxy-1-propanol as described in the present invention 4 characterized in that the concentration of a residual aldehyde compound in the crude solution is adjusted to not more than 0.5% by weight in the hydrogenation reaction.
The present invention 6 provides a method for the preparation of a high purity 3-alkoxy-1-propanol as described in the present invention 4 or 5, in which the 3-alkoxy-1-propanol is 3-methoxy-1-propanol.
The present invention 7 provides a method for the preparation of a high purity 3-alkoxy-1-propanol as described in the present invention 6, in which the alcoholic impurities are methanol and/or 2-methyl-1-pentanol.
The present invention 8 provides a solvent for a resist which comprises a solvent (a) which is a 1,3-propanediol alkylether, 1,3-propanediol alkylether acetate, or a mixture thereof.
The present invention 9 provides a solvent for a resist as described in the present invention 8, characterized in that the content of alcoholic impurities contained in the solvent (a) is not more than 0.3% by weight.
The present invention 10 provides a solvent for a resist as described in the present invention 8 or 9, in which the alcoholic impurities are 2-methyl-1-pentanol and/or methanol.
The present invention 11 provides a cleaning agent for a lithography composed of the solvent for a resist as described in any one of the present inventions 8-10.
The present invention 12 provides a cleaning agent for lithography as described in the present invention 11, characterized in that there are further contained linear or branched alcohols (b) having a carbon number of 2-4.
The present invention 13 provides a cleaning agent for lithography as described in the present invention 12, characterized in that the alcohols (b) are ethanol, 1-propanol, 2-propanol, or a mixture thereof.
The present invention 14 provides a cleaning agent for lithography as described in any one of the present inventions 11-13, characterized by comprising a homogeneous solvent containing solvents (c) of the group A described below.
Group A
Propylene glycol alkylether
Propylene glycol alkylether acetate
Ethylene glycol alkylether
Ethylene glycol alkylether acetate
Alkyl acetate
Alkyl propionate
Alkyl alkoxypropionate
Alkyl lactate
Aliphatic ketone
Alkoxybutanol, or
A mixture thereof
The present invention 15 provides a cleaning agent for lithography as described in the present invention 14, characterized in that the solvents of the group A are propylene glycol methylether, propylene glycol ethylether, propylene glycol propylether, propylene glycol methylether acetate, propylene glycol ethylether acetate, propylene glycol propylether acetate, ethylene glycol ethylether acetate, n-butyl acetate, methyl methoxypropionate, ethyl ethoxypropionate, 2-heptanone, methoxy butanol, and ethyl lactate, or a mixture thereof.
The present invention 16 provides a rinsing liquid for lithography comprising the solvent for a resist as described in any one of the present inventions 8-10 and water (d).
The present invention 17 provides a rinsing liquid for lithography as described in the present invention 16, characterized in that the water (d) is an ultra-high pure water.
The present invention 18 provides a rinsing liquid for lithography as described in the present invention 16 or 17, characterized by further containing a water-soluble organic solvent (d).
The present invention 19 provides a cleaning agent for lithography as described in the present invention 18, characterized in that the water-soluble organic solvents (d) are a solvent of the group Axe2x80x3 described below.
Group Axe2x80x3
Propylene glycol alkylether
Propylene glycol alkylether acetate
Ethyl lactate
Methylisobutyl ketone
Methylethyl ketone
Acetone, or
A mixture thereof
The present invention 20 provides a rinsing liquid for lithography as described in any one of the present inventions 16-19, in which the content of water is 0.5-200 parts by weight based on 100 parts by weight of total organic solvents.
The present invention 21 provides a rinsing liquid for lithography as described in any one of the present inventions 16-20, in which it is employed for rinsing a resist layer or a reflection protecting-layer.
The present invention 22 provides a solvent for a resist composition comprising the solvent for a resist as described in any one of the present inventions 8-10.
The present invention 23 provides a solvent for a resist composition as described in the present invention 22, characterized by further containing other solvents (cxe2x80x2) in the group Axe2x80x2 described below.
Group Axe2x80x2
Propylene glycol alkylether
Propylene glycol alkylether acetate
Alkyl acetate
Alkyl propionate
Alkyl alkoxypropionate
Alkyl lactate
Aliphatic ketone, or
A mixture thereof
The present invention 24 provides a resist composition comprising a resist resin (F) and the solvent for a resist composition as described in the present invention 22 or 23.
The present invention 25 provides a photo-resist composition for a printed circuit board comprising a modified copolymer (Bxe2x80x2) and the solvent for a resist composition as described in the present invention 22 or 23.
The present invention 26 provides a photo-resist composition for a printed circuit board as described in the present invention 25, characterized in that the modified copolymer (Bxe2x80x2) is a copolymer in which an epoxy group-contained unsaturated compound (Uc) having an aliphatic structure is added to carboxylic groups in a copolymer of a copolymerizable unsaturated carboxylic acid (Ua) with an unsaturated compound (Ub) other than the unsaturated carboxylic acid.